Abstract: Objective: To observe the efficacy of?distal tibial tuberosity - high tibial osteotomy combined with arthroscopy in the treatment of knee osteoarthritis with varus deformity, and to compare the efficacy with arthroscopy. Methods: 133 patients with medial compartment knee osteoarthritis were included in the study treated in our hospital from August 2012 to October 2018. The patients were divided into the arthroscopy combined with open-wedge high tibial osteotomy group (n=65) and the arthroscopy group (n=68) According to different treatment methods. Weight bearing line (WBL) and femora-tibial Angle (FTA) were recorded to assess the lower limb alignment before and 12 months after surgery. Visual analogue scale (VAS) scores, Hospital for Special Surgery (HSS) scores, and the Westrn Ontarioand Mcmaster Universities (WOMAC) scores were recorded to evaluate knee function before surgery and after surgery at 3 months and 12 months. Results: All 133 patients were followed up for more than 12 months. At 12 months after surgery, WBL in the combined group was improved from 16.34%±2.18% to 60.32%±2.89%, and FTA from 171.17°±1.87° to 179.83°±2.14° (p0.05). While there was no statistically significant difference with WBL and FTA in the arthroscopy group(p>0.05). At 3 months and 12 months after surgery; VAS, HSS and WOMAC scores in both groups were significantly improved compared with that before surgery(p0.05). VAS, HSS and WOMAC scores of the combined group were improved more significantly than those of the arthroscopy group, and the difference between the groups was statistically significant(p0.05). Conclusion: Distal tibial tuberosity - high tibial osteotomy combined with arthroscopy can effectively correct varus deformity, clean the lesions of the knee, and relieve symptoms. It has a more significant efficacy compared with arthroscopy.